This invention relates to rackets such as tennis rackets, and, more particularly, to the manufacture of rackets by injection molding of fiber-reinforced thermoplastic resins.
Racket sports, such as tennis, racketball, badminton, and squash, each utilize a racket with which a ball or other object is struck. Each of these types of rackets includes a head formed of a generally oval frame with strings supported thereon, a handle, and a throat that provides a transition between the handle and the head. The size and weight of the racket is tailored to the specific racket sport and the characteristics of the player.
In recent years, considerable effort has been devoted to improving both designs of the rackets and the materials of construction. Designs have been changed to increase the area of the racket head where the most satisfactory impact is achieved, the "sweet spot". Racket frames were traditionally made of wood or metal. More recently, fiber-reinforced composite materials have been used to form the frames of advanced rackets, providing improved strength and durability.
Although the available rackets have good performance, several problems remain. One is that the cost of advanced rackets is relatively high. Quality rackets generally retail for over $100, which places them in a price range above that which many persons and institutions such as schools can afford. Another is that high performance racket frames have not been optimized for fabrication from low-cost, recyclable materials. Tennis rackets, for example, must achieve satisfactory static and dynamic impact performance with a weight constrained to about 9-12 ounces, and also must be suitably robust for repeated use.
Thus, there is a need for even further improvements in the design and manufacturability of low-cost, high performance rackets. The present invention fulfills this need, and further provides related advantages.